Math Forum / Math Software / MATLAB / July 2008

I am new to Matlab.
I am using a parallel port that is connected to a device
that is supposed to give continous periodic highs and lows.
I have tried the timer function although I don't know if it

Hello, i am writing a program where i create a Matrix A that
is roughly 35000*6700 and storing it as a sparse matrix. It
is roughly 2% sparse. The way i am creating the matrix is i
make a full matrix AS (2% sparse) over a loop and i append

is it possible to change the color range of an image?
if i have obtained an image in which the color range is
[-8000 to 6000] and i want the colors to be in range [0
256] is it possible to convert the image to this range?

I am MSc student studying communication network planning &
management at the university of Portsmouth-UK...
I am doing simulation of a rang of multiplexing algorithms,
part of this program is the buffer, on of the things to do

Some days ago I posted on a problem that I was having with
compiling a simulink model using Real-Time Workshop:
http://www.mathworks.com/matlabcentral/newsreader/view_threa
d/172334#442216

I want to interface a simulink scheme with real hardware,
with a debian Linux. I want that simulink drives a process,
with a definite timestep. I can define this real time step
with the "setitimer" C function : so every 10ms, i can send

In one of my GUIs I needed to know how many lines I
could put in a listbox with all of the lines being
visible without scrolling. My first inclination was to
add one line at a time to the listbox until the scroll

 i want to remove the fist frame from frame sequence. Which
block should i use?
  For example, the input to the block is :
frame1  frame2  frame3...

I am a intermediate user of matlab and I need your help...
I try to calculate the explained variance for eof analysis,
but when I try to calculate the covariance matrix from my
data, matlab shown "out of memory". My data size is 126x8036

With MATLAB 2008a and Microsoft Visual C++ Express Edition,
I'm attempting to compile a GUIDE figure with a uitable in it.  

When I run my application, table_test.exe, I get a bunch of

I am trying to make an intercom type application where Voice is
recorded on CompA, sent over UDP to CompB, and played back on CompB in
real time with a slight delay.
I am recording my voice using wavrecord, then sending that data to

Hi, I need to find all possible solutions of the equation
a^2+b^2+c^2+d^2=1, the values of the variables (a/b/c/d)
will be within the range -1 to +1. It would be nice if
anyone please help in this regard. Thanks a lot in advance.

how to return the index of positive row?
For example,
A = [1 2 -3; 4 5 6; 7 9 -8];
I expect a function returenpositive(A) = 2;

Hi all,
may i know how do i assign to a series of variables?
for example i tried :
for k=1:100

between 0 & 1, and has a specified mean and standard
deviation. (Soemthing like a amplitude varying duty cycle